Computer and its types

What is Computer and its various types

Origin of Computer: –

The computer comes from Latin word “Computare” which means to calculate.

Compute is a Greek word which means to calculate.

By adding r in Compute = Computer mean Calculating machine.

Meaning of Computer: –

Computer is an electronic device that takes data / input from user, stores, process data and generates the required/ meaningful information (output) according to sets of instructions given by the users. It cannot think itself. A set of instructions that directs a computer to execute tasks is called a program or written by programmer. 

A computer is a device that works on IPO cycle.

Input -Input devices feed the computer the raw matter -facts or data.

Processing –The storage of data, numerical comparison, arithmetic operations are performed on data to produced desired results.

Output – The processed data or information is sent to the output device connected to computer.

 

INPUT →Encoder (Encoding)→ Processing→ Decoder (Decoding)→ OUTPUT

 

Basic Components of computer and it’s functions: –

Input Unit – Accepts data and instructions from the user and converts data into machine-readable from (binary). Input units are Keyboard, Mouse, Scanner, Microphone.

Central Processing Unit – CPU (Central Processing Unit) is known as the brain of computer. It processes data, performs calculations and control all operations.

ALU (Arithmetic Logic Unit) It performs arithmetic calculation or operations like additions, subtraction, multiplications etc. and performs logical operations (and, or, comparison etc).

CU (Control Unit) controls the working of all devices and directs data flow between memory and input/ output devices.

Memory or storage unit – Stores data, instructions and results.

Types of memory

Primary Memory – RAM is a temporary memory and ROM is a Permanent Memory.

Secondary Memory – Hard Disk, Pen Drive, CD/DVD.

 Output – Displays processed results and converts machine language into human readable Form. Output units are Monitor, Printer and Speakers.

 

Characteristics of Computer: –

Speed – Computers works at very high speed. It can process millions to billions of calculations per second thus carrying out even the complex asks in fractions of seconds. Time is measured in microseconds, nanoseconds and Pico seconds.

Accuracy- Computer System always produces results with valid data and instructions. A computer gives 100% accurate results if input and program is correct. Errors occurs only due to wrong data or wrong instructions (GIGO- Garbbage-In, Garbbage-Out)

Diligence – Computer does not get tired or bored. It can work for long hours without losing speed or accuracy. Computer does not process any intellectual power, only a user can determine what tasks a computer can perform as computer can’t take its own decisions.

Large storage Capacity- A computer can store huge amounts of data. Data can be stored in hard dis, SSD, Cloud storage etc. Storage is measured in KB, MB, GB, TB, TB, PB etc.

Versatility – Computers can do a variety of jobs depending on instructions fed to them and their hardware characteristics. It can be used for education, banking, typing, gaming. programming etc.

Reliability – Computers are highly reliable. They provide consistent results every time when the same input is given.

Automation – Once a program is started, the computer works automatically. No human intervention is required until the task is completed.

Productivity – Computers increase the productivity many times by reducing the repetitiveness needed in typewriter, Xeroxing, to be replaced by scanning and replacing many human workers with a single machine.

Multitasking – A computer can perform multiple tasks at the same time.

No IQ – A computer has no Intelligence of its own. It works according to instructions given by users quickly.

 

Types of Computers: –

On the basis on Size 

1. Embedded Computer – Theses are self-contained computing system with hardware and software designed for specific tasks within a large mechanical and electronic devices.

Or

An embedded computer is purpose built mini-computer that enables the core functionality of countless modern devices performs one or a limited set of dedicated tasks.

Features: –

• It works automatically and is programmed for a particular function.
• Built directly into a device for single use purpose.
• Compact and fit inside device.
• Often built on a microcontroller.
• Consume less power.
• Suitable to battery operated devices.
• Respond immediately to input.
• Limited Memory and Storage.
• Durable to withstand harsh environments like dust, heat, vibrations etc.
• Works continuously for long hours.
• The program instructions are typically stored in non-volatile memory chips (like ROM or Flash) and referred to as firmware.

Examples: –

Home appliances like microwave, ovens, washing machines, refrigerators, televisions, smart thermostats etc.

Automative likes Car engine control units (ECUs), anti-lock braking system (ABS), GPS navigation and in -vehicle system, infotainment system etc.

Industrial Automation Robotics, factory automation controls, specialised industrial PC’s.

Consumer goods like digital cameras, MP3 players smart devices, calculators and cellular phones.

Networking like routers and other communication devices like telephone.

Medical field pacemakers, MRI machines and patient monitoring equipment.

ATM machine to read ATM card, processes transaction and control cash dispenser.

 

2. Micro Computer- A micro-computer is a small single user computer that uses a microprocessor as its main processing unit.

It is the most common type of computer used today.

Microcomputer also called a Personal Computer.  

The micro computer revolution started in the mid 1970’s with early models like French developed Micral-N 1973, Canadian MCM/70 in 1974 and Altair 8800 in 1975.

Features: –

• Micro computers are small in size.
• Less costly.
• Easy to operate and supports GUI (Graphic User Interface).
• Microprocessor based – Single chip microprocessor as their CPU.
• Compact and portable computer.
• Designed for single user personal use.  
• These are short and fast computers.
• Less powerful than mini and mainframe computers.
• RAM capacity of these computers is from 2GB to 32 GB.

Types of microcomputers: –

Personal computers or Desktop

• The father of Personal computer Henry Edward Roberts.
• Other names for PC’s are PC-XT (Personal computer extended Technology) and PC-AT (Personal Computer Advanced Technology)

Workstations

• More powerful computer than other PC’s and with more storage capacity.
• They are used more in engineering, technical and graphics works.

Laptop

• Small size PC.
• Developed by Adam Asburn in 1981.
• IT houses a foldable LCD monitor, touchpad, keyboard, hard disk, CD/DVD drive and other ports.
• It uses a charged battery and work without electricity.
• Lithium -ion battery is used in laptop.

Notebook

• Notebook is the miniature version of laptop.
• The size of its monitor screen can be from 12 to 15 inch.
• Tablets.
• Touch screen-based device.

Palmtop

• Portable personal computer.
• The size is smaller than laptop.
• Voice is used instead of keyboard for input.
• It uses handheld operating system.

Smartphones

• Handheld microcomputer.

Wearable devices

• Smartwatches, Fitness band.

Uses of microcomputer: –

• Home use
• Education
• Gaming
• Office work
• Internet browsing
• Data Processing

Major companies of micro-computer are IBM, DELL, HCL, HP, APPLE, COMPAG, LENOVO, ZENITH etc.

 

3.Mini Computer– A mini-computer is a medium sized computer that is smaller than a mainframe but more powerful than a microcomputer (PC) It is designed to support multiple users at the same time. It is designed to support multiple users at the same time. There were very popular in 1960s-1980s for industrial and business use.

Features

• Multi user System.
• Moderate Processing Power.
• Smaller than mainframe.
• It can perform multi tasks at the same time.
• Cheaper than mainframe.
• Affordable in size and medium of organisation.
• Large storage capacity than microcomputers.

Uses: –

• Used in banking systems.
• Laboratories.
• Small and medium organisations.
• Universities and collages.
• Manufacturing industries.

Examples: – PDP (by DEC), IBM AS/400, VAX Systems.

 

4.Main Frame Computer: – Mainframe is a very large, powerful computer used by big organisation to process and manage a huge amount of data and support thousands of users at the same time.

Features: –

• Multi-users system – supports thousands of users simultaneously.
• Stored and handle huge amount of data.
• Works for 24×7.
• Supports many users.
• Very reliable.
• Very expensive.
• Required special environment and maintenance.
• Needed large space.
• Stored security system for sensitive data.
• Occupies a large room with cooling systems.
• Very high processing power – millions of Transactions per second.

Uses: –

• Mainly used by banks, railways, government offices, large hospitals and large business organisations.

 

5. Super Computer – Supercomputer is the fastest and most powerful type of computer. It is used to perform very complex calculations at extremely high speed.

Features: –

• Solve complex scientific problems.
• Fastest and more powerful.
• Extremely high speed. Speed measures in FLOPS.
• It can perform billions or trillions of calculations per second.
• Massive processing power.
• Requires high electricity.
• Stored and processed very large data sets.
• Many CPUs work at the same time on different parts of problem.
• Need a large room with special cooling systems.
• Costs millions and billions of rupees.

Uses: –

• Used for weather forecasting.
• Space research Like ISRO, NASA.
• Use in defence and nuclear.
• Medical Research and drug discovery.
• Earthquake and Tsunami prediction.

Examples: –

Frontier of USA, Fugaku of Japan

In India, PARAM series, Pratyush, Mihir

 

On the Basis of Work

1.Analog- A computer that works with continuous data (physical quantities) such as temperature, speed, pressure, voltage and current and gives real time results. It measures data in a continuous form, not in numbers like digital computers.

Features: –

• Fast measurement calculations.
• Give quick results for measurement-based problems.
• Real time input.
• Processes physical quantities that change continuously.
• Less accurate than digital-accuracy depends in measurement precision.
• Designed for specific tasks.
• Limited storage.
• Not suitable for complex logical operations.
• Shows results immediately as value changes.

Uses: –

• Scientific research
• Industrial process control
• Engineering calculations
• Weather measurement

Examples: –

• Thermometer to measure temperature.
• Analog ECG machine to measure heart activity.
• Speedometer to measure vehicle speed.
• Analog calculators.
• Voltmeter to measure voltage.

 

2. Digital- A computer that works with discrete data and processes information in the form of binary digits (0 and 1). It is most commonly used computer today.

Features: –

• Works on Binary System 0 and 1 for processing data.
• It can be programmed to perform different tasks.
• It can store huge amount of data.
• High accuracy.
• One programmed, works automatically.
• Performs millions and billions of calculations per second.

Examples: –

• Desktop, Laptop, smartphone

 

3. Hybrid – a computer that combines the features of both Analog and Digital computers. It can process continuous data like speed temperature and discrete data (0 and 1).

It is called hybrid because

Analog Part – it measures continuous physical values.

Digital part – Processes and stores data in binary form.

Features: –

• More expensive.
• Requires lots of maintenance
• Combines speed of Analog and accuracy of digital.
• Uses both type of processing Analog + Digital.
• Faster than pure Analog system.
• More accurate than Analog computers.
• Give quick response to changing inputs.
• More reliable for scientific and medical fields.

Uses: –

• Use in scientific research.
• Use in medical diagnosis.
• Space and defence.
• In industrial process control.

Examples: –

• ECG machine (to measure heart signals and display digital results)
• CT scan machine.
• ICU monitoring system.
• Petrol pump machine.
• Space research systems.

 

On the basis of Purposes: –

1.General purpose – General purpose computers are further divided into two types: –

    Scientific purpose computer and Business purpose computer.

2.Specific purposes – Special purpose computers are designed for specific tasks Example weather forecasting, in research etc.

 

On the basis of Generations

1.First Generation – From 1940-1956 (Vacuum based example ENIAC)

2.Second Generation – From 1956-1963 (Transistors)

3.Third Generation – From 1964- 1971 (Integrated Circuits)

4.Fourth Generation – From 1971-Present (Microprocessors)

5.Fifth Generation – From Present- Future (Artificial Intelligence)